Southern California -- this just in

One man was killed this morning and two of his relatives were injured when two commercial trucks collided, triggering a massive backup on the northbound Pacific Coast Highway in Pacific Palisades, authorities said.

The driver of a flatbed truck slammed into the back of another commercial truck and was killed instantly, Kelley said. He was reported dead on arrival when fire officials got to the scene, Kelley said. The front of his truck was completely flattened.

Neither truck was carrying cargo, Kelley said.

The deceased man was related to the driver and passenger in the truck he slammed into, Kelley said.They suffered minor injuries and were taken to a local hospital. Their gender and ages were unknown, Kelley said.

Traffic on Pacific Coast Highway was expected to be tied up for at least a couple of hours while crews cleaned up the wreckage, CHP officials said.